According to the development of electronic equipment industry, lighting devices including LEDs, PDPs, AMOLEDs and the like have been developed, and image devices, computers, mobile communication terminal or the like including the lighting devices have been also developed.
A printed circuit board to which a light source is mounted and which electrically connects electronic components, such as the light source and the like is used in the lighting devices. In particular, a bent-type substrate may be used so that light emitted from a light source element is incident to a side of a light guide plate.
However, when the bent-type substrate is manufactured, a printed circuit board on the substrate may be damaged at a bent part resulting from bending, namely, an insulating layer or a conductive pattern may be pressed or may be torn. Thus, it is problematic in that an electrical defect or a defect in appearance (the occurrence of foreign substances) occurs due to such damage.
In addition, the light guide plate is expanded due to heat generated from the light source element so that the light source element comes into contact with the expanded light guide plate. Thus, it is also problematic in that the light source element is damaged due to such contact.